It is known in many fields, for example in that of transfer devices for food products, to single and transport products, even of different dimensions and shapes, in order for them to be wrapped in protective packaging. On the basis of the technical characteristics, and sometimes on the chemical or physical characteristics, of the object to be transported and the type of packaging, various different automatic transfer devices are used.
One of the more widely used transfer systems of known type comprises transport means having a linear path, generally conveyor belts or rollers, which support and move objects of any shape and dimension from a retrieval source to a despatch outlet such as, for example, a packaging machine or a processing device. The conveyor belts may be combined with one another, for example in series or in parallel, in order to produce complex transfer systems, and are capable of working in a continuous cycle even with large quantities of objects. The conveyor belt transfer systems, however, are not particularly efficient at singling the objects transported, and frequently require further devices upstream or downstream of their path to achieve this aim.
Other transfer systems of known type comprise singling means which make it possible to transfer a single product, even of very small dimensions, by retrieving it from a position of origin and unloading it to a destination position. The retrieval means, which customarily comprise mobile articulated arms, have the principal advantage of working each time on single objects and of being able to carry out a very precise transfer in so far as they operate from and to spatial co-ordinates. In addition, compared with the conveyor belt systems, such retrieval means are not bound to a linear path. One of their principal drawbacks, however, consists precisely in the fact of being capable of transferring a single object at a time and of not being able to work rapidly with large quantities of objects.